Friction shock absorbing mechanism



June 33, 1945.

A. A. BUREAU FRICTION SHOCK ABSORBING MECHANISM Filed Feb. I 17, 1945 H T TOE- VE Y m 1 N Am a w K k in- W! Patented June 11, 1946 FRICTION snocx aasoaamo MECHANISM Arthur A. Bureau,

Chicago, Ill.,

asslgnor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application February 17, 1945, Serial No. 578,457

6 Claims.

This invention relates to a friction shock absorbing mechanism and more particularly to a draft gear for use in connecting a plurality of vehicles or railway cars.

In fraction draft gears of the type where friction shoes are used and are forced against a friction surface of a casing and moved therealong by a wedge member, the capacity of the draft gear may be increased by reducing the wedging angle of the wedge member to increase the transverse outward thrust ofthe shoes against the casing thereby increasing the frictional resistance to sliding movement between the shoes and the casing. However, difliculties arise in trying to increase the capacity of draft gears by this means beyond a certain point in that the wedge member becomes locked and will not release when the draft gear has been compressed and the pressure released.

An object of this invention is to provide an effective and freely releasable draft gear.

In one embodiment of the invention. there is provided a draft gear comprising a cylindrical housing with inner frictional surfaces against which a plurality of segmental friction shoes are adapted to be movedlongitudinally outward by a spring and moved longitudinally inward and radially outward by a hollow, slotted, pyramidal wedge member having flexible diverging wedge faces engaging cooperating inclined faces on the friction shoes. The wedge member is urged longitudinally outward by a spring and engages a follower which is movable relative to the housing.

The invention will be more fully understood from the following description taken in connection with the accompanying drawing illustrating a preferred embodiment, in which Fig. '1 is a vertical longitudinal section through a portion of a car body showing the draft gear in place thereon;

Fig. 2 is a horizontal section taken on the line 2-4 of Fig. 1;

Fig. 3 is an enlarged, fragmentary, vertical, sectional view showing a portion of the draft gear. and

Fig. 4 is an end view of the draft gear indicated by the line 5-4 of Fig. 3.

Referring to the drawing, there is shown in Fig. 1 a draft gear ill mounted on the underneath side of a vehicle body or railway car i l. The car it is provided with a pair of spaced, centrally located frame members l3 and H having secured thereto a pair of draft lugs l6 and I1 and a pair of buffer lugs l8 and IS. The draft gear in, located between the frame members l3 and I 4, is

positioned between and engages the draft lugs l6 and i1 and the buffer lugs l8 and I9 and is supported by plates 20-20 attached to the frame members I 3 and M.

The draft gear in comprises a cylindrical housing or casing 2i open at the forward end and closed at the rear end by an integral wall 22 which extends outwardly therefrom to form a rectangular follower engaging the buffer lugs I8 and IS. The shock absorbing mechanism is enclosed within the housing 2| and projects forward therefrom and abuts a followerblock 24 which engages the draft lugs l6 and IT. A yoke a coupler 21 by a key 28.

. 26 surrounds the draft gear and is connected to The housing 2i is provided with an inner cylindrical friction surface 3| against which a plurality of segmental friction shoes or members 33 slldably engage. Each of the shoes 33 is provided with an outer cylindrical friction surface for engaging the cylindrical surface iii of the housing and is provided with an inclined wedge face 35. The segmental shoes 33 are arranged adjacent each other so as to form an expansible cylindrical friction drum for frictionally engaging the housing, and with the flat inclined wedge faces 35 directed longitudinally outward and radially inward. as seen in Fig. 3. A helical compression spring 3?, enclosed within the housing and engaging the end wall 22 thereof, engages the ends of the shoes 33, urging them outward and opposthe wedge faces 35 of the shoes 33 and moves the shoes longitudinally inward and simultaneously force them radially outward when a force is applied theretoas will appear hereinafter. The wedge member to is provided with a plurality of fiat, converging, wall portions ti which are separated from adjacent wall portions M by slots (53 extending inwardly from the diverging ends thereof so as to provide a slight flexibility to each of the inclined wall portions 4!. The walls 4! have fiat wedge faces 64 thereon which may be disposed at an angle parallel to the faces 35 of the shoes 33 or they may be disposed at a slightly greater or lesser angle so as to initially engage the faces 35 at one end thereof. As shown in F g. 3 the faces 44 of the wedge member 40 are disposed at a slightly greater angle from the axis of the draft gear than the faces 35 so that they engage the faces 35 at the outer end thereof. One end of the wedge member 40 is provided with a seat 45 which engages an extension 46 of the follower block 24. 

